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QUESTION 4 2 points Save Answer A prospective observational study on the relationship between sleep deprivation and heart disease was done by Ayas, et al. (Arch Intern Med 2003). Women who slept at most 5 hours a night were compared to women who slept for 8 hours a night (reference group). After adjusting for potential confounding variables like smoking, a 95% confidence interval for the relative risk of heart disease was (1.10, 1.92). Based on this confidence interval, a consistent conclusion would be Oa. There was no evidence of an association between sleep deprivation and heart disease. O b. Lack of sleep causes the risk of heart disease to increase by 10% to 92%. c. Sleep deprivation is associated with a modestly decreased risk of heart disease. d. Sleep deprivation is associated with a modestly increased risk of heart disease. QUESTION 5 1 points Save Answer For the next two questions: It is known that for right-handed people, the dominant (right) hand tends to be stronger. For left-handed people who live in a world designed for right-handed people, the same may not be true. To test this, muscle strength was measured on the right and left hands of a random sample of 15 left-handed men and the difference (left - right) was found. The alternative hypothesis is one-sided (left hand stronger). The resulting t-statistic was 1.80. 15. This is an example of: Oa. An unpooled t-test. Ob. A paired t-test. c. A two-sample t-test. Od. A pooled t-test. QUESTION 6 2 points Save Answer Assuming the conditions are met, based on the t-statistic of 1.80 the appropriate conclusion for this test using a - .05 is: O a. Df = 14, so p-value > .05 and the null hypothesis cannot be rejected. Ob. Df = 14, so p-value .05 and the null hypothesis cannot be rejected